In the prior art, as a disaster recovery system of databases, a configuration is adopted where data is synchronized between databases located at remote locations. There are various methods for realizing synchronization control between databases, and update logs are used in many cases. For example, according to Patent Literature 1, when database is updated, the content of update of the database is stored as a sentence stated using a database language in an update log, and periodically, the sentences stored in the update logs are re-executed in the database of the synchronization destination (migration destination) to realize synchronization of data.
Patent Literature 2 discloses an example of a synchronization method that does not use update logs. This control method assigns an update frequency per synchronization target data, and performs synchronization in order from the data having smaller update frequencies.